EP2799823B1 - Laser output measuring apparatus - Google Patents
Laser output measuring apparatus Download PDFInfo
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- EP2799823B1 EP2799823B1 EP11878355.4A EP11878355A EP2799823B1 EP 2799823 B1 EP2799823 B1 EP 2799823B1 EP 11878355 A EP11878355 A EP 11878355A EP 2799823 B1 EP2799823 B1 EP 2799823B1
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- laser beam
- optical separator
- laser
- incident
- angle
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- 230000003287 optical effect Effects 0.000 claims description 167
- 238000002310 reflectometry Methods 0.000 claims description 52
- 230000007246 mechanism Effects 0.000 claims description 39
- 230000010287 polarization Effects 0.000 claims description 15
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- 239000011248 coating agent Substances 0.000 description 11
- 238000000576 coating method Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 9
- 238000005259 measurement Methods 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 3
- 238000002834 transmittance Methods 0.000 description 3
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- 238000011144 upstream manufacturing Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/4257—Photometry, e.g. photographic exposure meter using electric radiation detectors applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
- G01J1/0411—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
- G01J1/0414—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings using plane or convex mirrors, parallel phase plates, or plane beam-splitters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
- G01J1/0429—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings using polarisation elements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
- G01J1/0448—Adjustable, e.g. focussing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/02—Details
- G01J1/04—Optical or mechanical part supplementary adjustable parts
- G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
- G01J1/0474—Diffusers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
- G01J1/20—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle
- G01J1/22—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means
Definitions
- the present invention relates to a laser output measuring apparatus for measuring an intensity of a laser beam in adjusting an output of the laser beam oscillated from a laser oscillator.
- an intensity of the laser beam oscillated from the laser oscillator is measured using a laser output measuring apparatus.
- Fig. 12 is a configuration diagram showing a conventional laser output measuring apparatus disclosed in the following Patent Document 1.
- the conventional laser output measuring apparatus is configured with an optical separator 102 that reflects a part of a laser beam emitted from a laser oscillator 101 as a monitoring beam, and a photodetector 103 that detects an intensity of a reflected beam from the optical separator 102.
- the intensity measured by the photodetector 103 is fed back to the laser oscillator 101, and the output of the laser beam is adjusted according to a measurement result of the intensity.
- the laser beam transmitted through the optical separator 102 is used for an original purpose of the laser beam.
- the optical separator 102 is disposed in a state inclined at a predetermined angle (usually, inclined at 45°) with respect to a direction of an optical axis 104 of the laser beam emitted from the laser oscillator 101.
- a partially reflective coating of a dielectric multilayer film is usually applied thereon.
- the partially reflective coating serves to reflect the part of the laser beam for the purpose of measuring an intensity of the laser beam, it is usually the coating in a low reflectivity region.
- the dielectric film of the partially reflective coating has a property in which the reflectivity changes due to absorption of atmospheric moisture or due to temperature.
- the photodetector 103 detects the intensity of the laser beam reflected by the optical separator 102 as mentioned above; however, when the laser beam emitted from the laser oscillator 101 enters the optical separator 102, an incident angle of the laser beam differs depending on an incident position thereon, so that the reflectivity of the laser beam reflected by the optical separator 102 differs depending on the incident position. For this reason, it is difficult to measure accurately the output of the laser beam emitted from the laser oscillator 101.
- Patent Document 1 Japanese Patent Application Laid-open No. H04(1992)-220535 (paragraph number [0008], Fig. 1 ) Further, document JP2007214189 discloses a device for monitoring the polarization state of a laser beam wherein a tilted optical separator is rotated about an optical axis of the laser beam.
- the conventional laser output measuring apparatus is configured as mentioned above, due to the occurrence of deterioration in the dielectric film of the partially reflective coating applied on the reflection surface of the optical separator 102, even though the reflectivity thereof changes slightly, a large output change in the reflected laser beam occurs. For this reason, there is a problem such that an accurate measurement for the intensity of the laser beam is difficult.
- the method that applies the coating of the metal film on the reflection surface of the optical separator 102 is taken into consideration; however, even in this case, the formation of the film is costly, which poses a problem to make the laser output measuring apparatus expensive.
- the present invention has been made to solve the foregoing problems, and an object of the invention is to provide a laser output measuring apparatus that can measure accurately the intensity of the converged laser beam without using an expensive optical separator.
- a laser output measuring apparatus is defined in claim 1.
- Fig. 1 is a side view showing a laser output measuring apparatus according to Embodiment 1 of the present invention.
- a laser oscillator 1 is the oscillator that oscillates a laser beam.
- the laser beam oscillated from the laser oscillator 1 is a substantially linearly polarized laser beam.
- the P-wave and S-wave of the laser beam except for a completely non-polarized beam are made incident on the optical separator 3 at a fixed ratio, it is applicable to the present invention.
- a lens 2 is an optical component that converges the laser beam oscillated from the laser oscillator 1.
- the optical separator 3 is an optical component that reflects a part of the laser beam converged by the lens 2 according to a Fresnel reflectivity that depends on a polarization direction and an incident angle thereon of the laser beam.
- the optical separator 3 is disposed in a position that is rotated by a predetermined angle ⁇ 1 about an optical axis of the laser beam converged by the lens 2 (in an arrow A direction), and further rotated by a predetermined angle ⁇ 2 about a straight line (in an arrow B direction) perpendicular to the optical axis 6 of the laser beam and an incident surface of the laser beam (reflection surface of the optical separator 3).
- a diffuser plate 4 is disposed on a path of the laser beam reflected by the optical separator 3, and is an optical component that diffuses the laser beam and makes the diffused light of the laser beam incident on a photodetector 5.
- the photodetector 5 is disposed in the post stage of the diffuser plate 4,and is the detector that measures an intensity of the laser beam diffused by the diffuser plate 4.
- optical separator 3, diffuser plate 4, and photodetector 5 are integrally configured with each other, so that the diffuser plate 4 and photodetector 5 are rotated integrally with the optical separator 3 when the optical separator 3 is rotated by angle adjusting mechanisms 7, 8 described later.
- the angle adjusting mechanism 7 that is a first angle adjusting mechanism is an actuator that rotates the optical separator 3 by the predetermined angle ⁇ 1 about the optical axis of the laser beam converged by the lens 2 (in the arrow A direction).
- the angle adjusting mechanism 8 that is a second angle adjusting mechanism is an actuator that rotates the optical separator by the predetermined angle ⁇ 2 about the straight line (in the arrow B direction) perpendicular to the optical axis 6 of the laser beam converged by the lens 2 and the incident surface of the laser beam (reflection surface of the optical separator 3).
- the lens 2 converges the laser beam.
- the optical separator 3 reflects a part of the laser beam converged by the lens toward the diffuser plate 4, and transmits the other laser beam.
- the reflection of the laser beamby the optical separator 3 is made based on the Fresnel reflectivity that depends on the polarization direction of the laser beam and the incident angle of the laser beam.
- the Fresnel reflectivity is adjusted such that the angle adjusting mechanisms 7, 8 rotate the optical separator 3.
- Fig. 2 is a side view showing a rotation about the optical axis of the laser beam by the angle adjusting mechanism 7
- Fig. 3 is a perspective view showing the rotation about the optical axis of the laser beam by the angle adjusting mechanism 7.
- Fig. 4 is an illustration diagram showing an adjustment of a ratio of a vertical polarization wave (P-wave) and a horizontal polarization wave (S-wave) in the laser beam by the angle adjusting mechanism 7.
- the angle adjusting mechanism 7 rotates the optical separator 3 by the predetermined angle ⁇ 1 (rotation in a range from 0° to 90°) about the optical axis of the laser beam converged by the lens 2 (in the arrow A direction) to thereby adjust the Fresnel reflectivity of the optical separator 3.
- Fig. 5 is a top view showing a rotation about a straight line perpendicular to an optical axis 6 of the laser beam and the incident surface of the laser beam by the angle adjusting mechanism 8
- Fig. 6 is a perspective view showing a rotation about the straight line perpendicular to the optical axis 6 of the laser beam and the incident surface of the laser beam by the angle adjusting mechanism 8.
- the angle adjusting mechanism 8 rotates the optical separator by the predetermined angle ⁇ 2 (rotation in the range from 0° to 90°) about a straight line 9 (in the arrow B direction) perpendicular to the optical axis 6 of the laser beam converged by the lens 2 and the incident surface of the laser beam (reflection surface of the optical separator 3) to thereby adjust a reflectivity of the p-polarization component and a reflectivity of the s-polarization component of the optical separator 3.
- the angle ⁇ 2 of the optical separator 3 is adjusted by the angle adjusting mechanism 8, the incident angle of the laser beam incident on the reflection surface of the optical separator 3 is adjusted.
- the reflectivity of the p-polarization component and the reflectivity of the s-polarization component are determined according to the incident angle of the laser beam on the optical separator 3, it is possible to adjust the reflectivity of the p-polarization component and the reflectivity of the s-polarization component when the optical separator 3 is rotated about the straight line 9 (in arrow B-direction) by the angle adjusting mechanism 8.
- the optical separator 3 For the respective vertical polarization wave (P-wave) and horizontal polarization wave (S-wave) in the incident laser beam, the optical separator 3 has reflectivities of R P and R S that depend on a refraction index of the material of the reflection surface.
- the reflectivities R p , R s in the optical separator 3 are determined by the refraction index n of the material of the reflection surface and the incident angle ⁇ 0 of the laser beam to the optical separator 3.
- the total reflectivity of the optical separator 3 is determined according to the ratio of the vertical polarization wave (P-wave) and the horizontal polarization wave (S-wave) in the incident laser beam.
- Total reflectivity of the optical separator 3 Rate of P ⁇ wave component * Reflecivity R P of P ⁇ wave + Rate of S ⁇ wave component * Reflectivity R S of S ⁇ wave + Rate of P ⁇ wave component * Transmittance T P of P ⁇ wave * Reflecivity R P of P ⁇ wave + * Rate of S ⁇ wave component * Transmittance T S of S ⁇ wave * Reflecivity R S of S ⁇ wave
- the first and second terms represent the beams in which the P-wave and S-wave are reflected on the reflection surface
- the third and fourth terms represent the beams that pass through the optical separator 3 to be reflected at the one-side end face.
- T S 1 - R S .
- Fig. 7 is an illustration diagram showing that when the laser beam converged by the lens 2 is made incident on the optical separator 3, the incident angle changes depending on the incident position.
- the incident angle changes depending on the incident position, as shown in Fig. 7 .
- the laser beam at the center position O of the optical separator 3 has the beam vector V O along the optical axis 6 (z-axis), whereas the laser beam at the point P of the optical separator 3 has the beam vector V P at an angle deviated by ⁇ from the optical axis 6.
- a polarized beam vector of the laser beam incident on the point P is defined as " ⁇ "
- a normal vector of the optical separator 3 is defined as "N”.
- this angle ⁇ 3 can be determined by calculating an inner product or an outer product of the beam vector V P and the normal vector N.
- the incident angle ⁇ 0 of the laser beam to the optical separator 3 and the angle ⁇ 3 between the beam vector V P and the normal vector N have the following relationship, the incident angle ⁇ 0 of the laser beam is obtained.
- ⁇ 0 ⁇ 3 ⁇ 180 °
- the outer product V P * N of the beam vector V P and the normal vector N has a direction perpendicular to the incident surface, it corresponds to an s-polarization direction of the laser beam incident on the optical separator 3.
- V P * N a unit vector of V P * N is defined as "e s " (unit vector in the s-polarization direction of the incident laser beam).
- a ratio of a P-wave component and an S-wave component in the incident laser beam can be determined by solving the polarized beam vector ⁇ into a direction of the unit vector e p , in the p-polarization direction, and a direction of the unit vector e s in the s-polarization direction.
- Fig. 9 is an illustration diagram showing a relationship between the deviated angle ⁇ from the optical axis 6 of the laser beam to be incident on the optical separator 3 and a reflectivity thereof.
- the reflectivity depending on the incident position ranges from 0% to 4.5%, which varies greatly.
- the reflectivity depending on the incident position ranges from 2.4% to 5.9%.
- the reflectivity depending on the incident position ranges from 3.1% to 4.7%.
- the diffuser plate 4 is disposed on the path of the laser beam reflected by the optical separator 3 in which the angles ⁇ 1 , ⁇ 2 are adjusted (the optical separator in which the reflectivity is averaged with respect to the deviation ⁇ of the laser beam from the optical axis 6) ; thus, the laser beam reflected by the optical separator 3 is uniformly diffused, and such diffused beam of the laser beam is made incident on the photodetector 5.
- the photodetector 5 is disposed in the post stage of the diffuser plate 4, and measures an intensity of the laser beam diffused by the diffuser plate 4.
- Embodiment 1 since the photodetector 5 is disposed in the post stage of the diffuser plate 4, it is possible to accurately make a constant fraction of the beam incident on the photodetector 5 without changing the position of the photodetector 5, even when the optical path of the reflected beam is changed at the time of adjusting the angle of the optical separator 3, or the spatial energy distribution of the laser beam is non-uniform. Thus, it becomes possible to accurately measure the intensity of the laser beam.
- the aperture area of the photodetector 5 since the laser beam is diffused by the diffuser plate 4, there is no limit for the aperture area of the photodetector 5; however, in order to measure the power accurately, it is desirable that the aperture area of the photodetector 5 be smaller than the diffused area of the laser beam.
- the optical separator 3, diffuser plate 4, and photodetector 5 are configured integrally with each other. This is made to prevent the reflected beam from being not incident on the diffuser plate 4 and the photodetector 5 when the optical path of the reflected beam is changed with the angle adjustment of the optical separator 3.
- optical separator 3 since the optical separator 3, diffuser plate 4, and photodetector 5 are moved integrally, it is possible to make the reflected beam incident on the diffuser plate 4 and photodetector 5, even when a deviation of the optical path occurs with the angle adjustment of the optical separator 3.
- the reflected beam is similarly rotated by the angle ⁇ 1 about the optical axis 6, whereas when it is rotated by the angle ⁇ 2 about the straight line 9 perpendicular to the optical axis 6 of the laser beam and the incident surface of the laser beam, the reflected beam is rotated by the angle 2 * ⁇ 2 about the straight line 9.
- the optical separator 3 having a smaller reflectivity is desirable in order not to reduce as much as possible the output of the laser beam to be originally output.
- a rate of the laser beam to be separated by the optical separator 3 is a degree such that no measurement error in the photodetector 5 occurs.
- the reflectivity of the optical separator 3 be as small as possible and adjustable for every apparatus, it becomes possible to adjust the rate of the laser beam to be separated by the optical separator 3 for every apparatus by changing the rotation angle of the optical separator 3 using the angle adjusting mechanisms 7, 8.
- Embodiment 1 since it is configured such that the optical separator 3 is disposed in the position that is rotated by the predetermined angle about the optical axis 6 of the laser beam converged by the lens 2, and further rotated by the predetermined angle about the straight line 9 perpendicular to the optical axis 6 of the laser beam and the incident surface of the laser beam, there is rendered an advantageous effect that can measure accurately an intensity of the laser beam without using an expensive optical separator.
- the angle adjusting mechanisms 7, 8 adjust the angles ⁇ 1 , ⁇ 2 of the optical separator 3; however, if the position in which the reflectivities of the optical separator 3 are averaged with respect to the deviations ⁇ of the laser beam from the optical axis 6 is found in advance, the optical separator 3 may be fixed at that position; thus, in this case, the angle adjusting mechanisms 7, 8 for adjusting the angles ⁇ 1 , ⁇ 2 of the optical separator 3 become unnecessary.
- the number of components can be reduced to thereby achieve cost reduction. Further, since the movable parts can be reduced, it is possible to enhance reliability of the laser output measuring apparatus.
- Fig. 10 is a side view showing a laser output measuring apparatus according to Embodiment 2 of the present invention.
- the same reference numerals as those in Fig. 1 represent the same or equivalent parts, so that descriptions therefor will be omitted.
- N is an integer of 2 or more
- laser oscillators 10 1 , 10 2 , ⁇ , 10 N are equipped.
- Fig. 11 is a side view showing a state in which a beam vector V N of the laser beam oscillated from the laser oscillator 10 N is made incident at a deviated angle ⁇ with respect to the optical axis 6.
- the laser beam oscillated from the N laser oscillators 10 1 to 10 N is made incident on the lens 2.
- the beam vector V N of the laser beam oscillated from the laser oscillator 10 N is made incident at the deviated angle ⁇ relative to the optical axis 6, as shown in Fig. 11 .
- the reflectivity of the optical separator 3 is calculated as described in the above Embodiment 1 from the above formulae (1) to (3) on the basis of the angle ⁇ from the optical axis 6.
- the laser output measuring apparatus is suited to a case where in adjusting an output of the laser beam oscillated from the laser oscillator, the intensity of the laser beam needs to be measured.
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Description
- The present invention relates to a laser output measuring apparatus for measuring an intensity of a laser beam in adjusting an output of the laser beam oscillated from a laser oscillator.
- Heretofore, in adjusting an output of a laser beam oscillated from a laser oscillator, an intensity of the laser beam oscillated from the laser oscillator is measured using a laser output measuring apparatus.
-
Fig. 12 is a configuration diagram showing a conventional laser output measuring apparatus disclosed in the following Patent Document 1. - As shown in
Fig. 12 , the conventional laser output measuring apparatus is configured with anoptical separator 102 that reflects a part of a laser beam emitted from alaser oscillator 101 as a monitoring beam, and aphotodetector 103 that detects an intensity of a reflected beam from theoptical separator 102. - The intensity measured by the
photodetector 103 is fed back to thelaser oscillator 101, and the output of the laser beam is adjusted according to a measurement result of the intensity. - On the other hand, the laser beam transmitted through the
optical separator 102 is used for an original purpose of the laser beam. - In this case, the
optical separator 102 is disposed in a state inclined at a predetermined angle (usually, inclined at 45°) with respect to a direction of anoptical axis 104 of the laser beam emitted from thelaser oscillator 101. - Further, in order for a reflection surface of the
optical separator 102 to have an intended reflectivity, a partially reflective coating of a dielectric multilayer film is usually applied thereon. - Since the partially reflective coating serves to reflect the part of the laser beam for the purpose of measuring an intensity of the laser beam, it is usually the coating in a low reflectivity region.
- The dielectric film of the partially reflective coating has a property in which the reflectivity changes due to absorption of atmospheric moisture or due to temperature.
- For example, when the
optical separator 102 of 1% in reflectivity (99% in transmission) is used, a change of 0.1% in reflectivity results in an output change of 10% (= 0.1%/1.0%) in the output change of the laser beam reflected by theoptical separator 102. - Accordingly, even though deterioration occurs in the dielectric film of the partially reflective coating, and the reflectivity thereof varies slightly, a large output change in the reflected laser beam occurs.
- Incidentally, the following is known: it is difficult to control a dielectric film having a low reflectivity, so that a large variation thereof occurs, and also the formation of the film is costly.
- In the conventional laser output measuring apparatus, the
photodetector 103 detects the intensity of the laser beam reflected by theoptical separator 102 as mentioned above; however, when the laser beam emitted from thelaser oscillator 101 enters theoptical separator 102, an incident angle of the laser beam differs depending on an incident position thereon, so that the reflectivity of the laser beam reflected by theoptical separator 102 differs depending on the incident position. For this reason, it is difficult to measure accurately the output of the laser beam emitted from thelaser oscillator 101. - Thus, instead of the dielectric multilayer involving a larger variation in reflectivity depending on the incident angle, a method that applies a coating of a metal film on the reflection surface of the
optical separator 102 is considered; however, even in this case, the formation of the film is costly, which makes the laser output measuring apparatus expensive. - Patent Document 1: Japanese Patent Application Laid-open No.
H04(1992)-220535 Fig. 1 ) Further, documentJP2007214189 - Since the conventional laser output measuring apparatus is configured as mentioned above, due to the occurrence of deterioration in the dielectric film of the partially reflective coating applied on the reflection surface of the
optical separator 102, even though the reflectivity thereof changes slightly, a large output change in the reflected laser beam occurs. For this reason, there is a problem such that an accurate measurement for the intensity of the laser beam is difficult. - In addition, it is difficult to control the dielectric film in a low reflectivity; a large variation thereof occurs, and also the formation of the film is costly, which poses a problem to make the laser output measuring apparatus expensive.
- Further, in a case where it is desired to measure the output at a beam converged position, when a lens for convergence is disposed upstream of the optical separator, an angle of the converged laser beam incident on the optical separator differs depending on the incident position, and thus the reflectivity of the laser beam varies depending on the incident position. For this reason, taking into consideration, for instance, an output variation due to deterioration of the lens for convergence, there is a problem that it is difficult to observe the output at the beam converged position.
- Thus, instead of the dielectric multilayer film involving a larger variation in reflectivity depending on the incident angle, the method that applies the coating of the metal film on the reflection surface of the
optical separator 102 is taken into consideration; however, even in this case, the formation of the film is costly, which poses a problem to make the laser output measuring apparatus expensive. - The present invention has been made to solve the foregoing problems, and an object of the invention is to provide a laser output measuring apparatus that can measure accurately the intensity of the converged laser beam without using an expensive optical separator.
- A laser output measuring apparatus according to the present invention is defined in claim 1.
- According to the present invention, as defined in claim 1, there is an advantageous effect that can measure accurately an intensity of the converged laser beam without using an expensive optical separator.
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Fig. 1 is a side view showing a laser output measuring apparatus according to Embodiment 1 of the present invention. -
Fig. 2 is a side view showing a rotation about an optical axis of a laser beam by an angle adjusting mechanism 7. -
Fig. 3 is a perspective view showing the rotation about the optical axis of the laser beam by the angle adjusting mechanism 7. -
Fig. 4 is an illustration diagram showing an adjustment of a ratio of a vertical polarization wave (P-wave) and a horizontal polarization wave (S-wave) of the laser beam by the angle adjusting mechanism 7. -
Fig. 5 is a top view showing a rotation about the optical axis of the laser beam, and a straight line perpendicular to an incident surface of the laser beam by anangle adjusting mechanism 8. -
Fig. 6 is a perspective view showing the rotation about the optical axis of the laser beam, and the straight line perpendicular to the incident surface of the laser beam by theangle adjusting mechanism 8. -
Fig. 7 is an illustration diagram showing that when the laser beam converged by alens 2 is made incident on anoptical separator 3, an incident angle changes depending on an incident position thereof. -
Fig. 8 is an illustration diagram showing an angle θ3 between a beam vector Vp and a normal vector N. -
Fig. 9 is an illustration diagram showing a relationship between a deviation angle Δθ from the optical axis of the laser beam made incident on theoptical separator 3 and a reflectivity thereof. -
Fig. 10 is a side view showing a laser output measuring apparatus according toEmbodiment 2 of the invention. -
Fig. 11 is a side view showing a state in which a beam vector VN of a laser beam oscillated from alaser oscillator 10N is made incident at a deviation angle Δθ with respect to anoptical axis 6. -
Fig. 12 is a configuration diagram showing a conventional laser output measuring apparatus disclosed in Patent Document 1. -
Fig. 1 is a side view showing a laser output measuring apparatus according to Embodiment 1 of the present invention. - In
Fig. 1 , a laser oscillator 1 is the oscillator that oscillates a laser beam. - However, since a P-wave and an S-wave of the laser beam oscillated from the laser oscillator 1 to be made incident on an
optical separator 3 are required to be incident thereon at a fixed ratio without a temporal change, in this Embodiment 1, it is assumed that the laser beam oscillated from the laser oscillator 1 is a substantially linearly polarized laser beam. - Incidentally, since the P-wave and S-wave of the laser beam except for a completely non-polarized beam are made incident on the
optical separator 3 at a fixed ratio, it is applicable to the present invention. - A
lens 2 is an optical component that converges the laser beam oscillated from the laser oscillator 1. - The
optical separator 3 is an optical component that reflects a part of the laser beam converged by thelens 2 according to a Fresnel reflectivity that depends on a polarization direction and an incident angle thereon of the laser beam. - A partially reflective coating is not applied on a reflection surface of the
optical separator 3. Instead, theoptical separator 3 is disposed in a position that is rotated by a predetermined angle θ1 about an optical axis of the laser beam converged by the lens 2 (in an arrow A direction), and further rotated by a predetermined angle θ2 about a straight line (in an arrow B direction) perpendicular to theoptical axis 6 of the laser beam and an incident surface of the laser beam (reflection surface of the optical separator 3). - A
diffuser plate 4 is disposed on a path of the laser beam reflected by theoptical separator 3, and is an optical component that diffuses the laser beam and makes the diffused light of the laser beam incident on aphotodetector 5. - The
photodetector 5 is disposed in the post stage of thediffuser plate 4,and is the detector that measures an intensity of the laser beam diffused by thediffuser plate 4. - Note that the
optical separator 3,diffuser plate 4, andphotodetector 5 are integrally configured with each other, so that thediffuser plate 4 andphotodetector 5 are rotated integrally with theoptical separator 3 when theoptical separator 3 is rotated byangle adjusting mechanisms 7, 8 described later. - The angle adjusting mechanism 7 that is a first angle adjusting mechanism is an actuator that rotates the
optical separator 3 by the predetermined angle θ1 about the optical axis of the laser beam converged by the lens 2 (in the arrow A direction). - The
angle adjusting mechanism 8 that is a second angle adjusting mechanism is an actuator that rotates the optical separator by the predetermined angle θ2 about the straight line (in the arrow B direction) perpendicular to theoptical axis 6 of the laser beam converged by thelens 2 and the incident surface of the laser beam (reflection surface of the optical separator 3). - Next, an operation thereof will be described.
- When the laser oscillator 1 oscillates the laser beam, the
lens 2 converges the laser beam. - The
optical separator 3 reflects a part of the laser beam converged by the lens toward thediffuser plate 4, and transmits the other laser beam. - Here, the reflection of the laser beamby the
optical separator 3 is made based on the Fresnel reflectivity that depends on the polarization direction of the laser beam and the incident angle of the laser beam. - The Fresnel reflectivity is adjusted such that the
angle adjusting mechanisms 7, 8 rotate theoptical separator 3. - In the following, a description will be given of an adjustment in reflectivity of the
optical separator 3 by theangle adjusting mechanisms 7, 8. -
Fig. 2 is a side view showing a rotation about the optical axis of the laser beam by the angle adjusting mechanism 7, andFig. 3 is a perspective view showing the rotation about the optical axis of the laser beam by the angle adjusting mechanism 7. - Further,
Fig. 4 is an illustration diagram showing an adjustment of a ratio of a vertical polarization wave (P-wave) and a horizontal polarization wave (S-wave) in the laser beam by the angle adjusting mechanism 7. - The angle adjusting mechanism 7 rotates the
optical separator 3 by the predetermined angle θ1 (rotation in a range from 0° to 90°) about the optical axis of the laser beam converged by the lens 2 (in the arrow A direction) to thereby adjust the Fresnel reflectivity of theoptical separator 3. - Here, as shown in
Fig. 4 , the laser beam incident on theoptical separator 3 is assumed to have only a p-polarization component when the angle θ1 = 0°. - At this time, when the angle adjusting mechanism 7 rotates the
optical separator 3 in the arrow A direction, an s-polarization component emerges, whereas the p-polarization component decreases. - Thereafter, when the angle θ1 = 90° is performed, as shown in
Fig. 4 , the p-polarization component vanishes, while only the s-polarization component remains. - Thus, when the angle adjusting mechanism 7 rotates the
optical separator 3 in the arrow A direction, it is possible to adjust the ratio of the vertical polarization wave (P-wave) and the horizontal polarization wave (S-wave) in the laser beam. -
Fig. 5 is a top view showing a rotation about a straight line perpendicular to anoptical axis 6 of the laser beam and the incident surface of the laser beam by theangle adjusting mechanism 8, andFig. 6 is a perspective view showing a rotation about the straight line perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam by theangle adjusting mechanism 8. - The
angle adjusting mechanism 8 rotates the optical separator by the predetermined angle θ2 (rotation in the range from 0° to 90°) about a straight line 9 (in the arrow B direction) perpendicular to theoptical axis 6 of the laser beam converged by thelens 2 and the incident surface of the laser beam (reflection surface of the optical separator 3) to thereby adjust a reflectivity of the p-polarization component and a reflectivity of the s-polarization component of theoptical separator 3. - That is, when the angle θ2 of the
optical separator 3 is adjusted by theangle adjusting mechanism 8, the incident angle of the laser beam incident on the reflection surface of theoptical separator 3 is adjusted. - Since the reflectivity of the p-polarization component and the reflectivity of the s-polarization component are determined according to the incident angle of the laser beam on the
optical separator 3, it is possible to adjust the reflectivity of the p-polarization component and the reflectivity of the s-polarization component when theoptical separator 3 is rotated about the straight line 9 (in arrow B-direction) by theangle adjusting mechanism 8. - Here, since the partially reflective coating is not applied on the reflection surface of the
optical separator 3, a Fresnel reflection occurs on the reflection surface. - For the respective vertical polarization wave (P-wave) and horizontal polarization wave (S-wave) in the incident laser beam, the
optical separator 3 has reflectivities of RP and RS that depend on a refraction index of the material of the reflection surface. - When the refraction index of the material of the reflection surface in the
optical separator 3 is defined as "n", and the incident angle of the laser beam to theoptical separator 3 is defined as "θ0", the reflectivities of RP and RS of the beam at the boundary between air and theoptical separator 3 are represented by the following formulae (1) and (2). -
- ·Reflectivity RP for P-wave
- ·Reflectivity RS for S-wave
- From the formulae (1) and (2), it can be seen that the reflectivities Rp, Rs in the
optical separator 3 are determined by the refraction index n of the material of the reflection surface and the incident angle θ0 of the laser beam to theoptical separator 3. - Then, the total reflectivity of the
optical separator 3 is determined according to the ratio of the vertical polarization wave (P-wave) and the horizontal polarization wave (S-wave) in the incident laser beam. -
- In the formula (3), the first and second terms represent the beams in which the P-wave and S-wave are reflected on the reflection surface, and the third and fourth terms represent the beams that pass through the
optical separator 3 to be reflected at the one-side end face. - Further, with respect to Reflectivity RP of P-wave, Transmittance TP of P-wave has a relationship of TP = 1 - RP, and with respect to the S-wave, similarly, there is provided a relationship of TS = 1 - RS.
-
Fig. 7 is an illustration diagram showing that when the laser beam converged by thelens 2 is made incident on theoptical separator 3, the incident angle changes depending on the incident position. - When the laser beam converged by the
lens 2 is made incident on theoptical separator 3, the incident angle changes depending on the incident position, as shown inFig. 7 . - For example, when a beam vector VO at the center position O of the
optical separator 3 is compared with a beam vector VP of the laser beam incident on a point P, it can be seen that the incident angle to theoptical separator 3 differs depending on the incident position. - As mentioned above, what the incident angle to the
optical separator 3 differs depending on the incident position causes a problem that the reflectivity of the laser beam differs depending on the position of theoptical separator 3, which hinders a stable laser output measurement. - The laser beam at the center position O of the
optical separator 3 has the beam vector VO along the optical axis 6 (z-axis), whereas the laser beam at the point P of theoptical separator 3 has the beam vector VP at an angle deviated by Δθ from theoptical axis 6. - Here, a polarized beam vector of the laser beam incident on the point P is defined as "ε", and a normal vector of the
optical separator 3 is defined as "N". - However, it is assumed that the beam vectors VO, VP and the polarized beam vector ε have no components in the direction of the straight line 9 (y-axis).
- As shown in
Fig. 8 , when an angle between the beam vector VP and the normal vector N is defined as θ3, this angle θ3 can be determined by calculating an inner product or an outer product of the beam vector VP and the normal vector N. -
- Further, since the outer product VP * N of the beam vector VP and the normal vector N has a direction perpendicular to the incident surface, it corresponds to an s-polarization direction of the laser beam incident on the
optical separator 3. - Here, a unit vector of VP * N is defined as "es" (unit vector in the s-polarization direction of the incident laser beam).
- At this time, since a p-polarization direction thereof is perpendicular to the s-polarization direction and the incident direction, it is represented by an outer product VP * es of the beam vector VP and the unit vector es in the s-polarization direction.
- Additionally, when a unit vector of the incident laser beam in the p-polarization direction is defined as ep (= VP * es), a ratio of a P-wave component and an S-wave component in the incident laser beam can be determined by solving the polarized beam vector ε into a direction of the unit vector ep, in the p-polarization direction, and a direction of the unit vector es in the s-polarization direction.
-
Fig. 9 is an illustration diagram showing a relationship between the deviated angle Δθ from theoptical axis 6 of the laser beam to be incident on theoptical separator 3 and a reflectivity thereof. - In
Fig. 9 , calculation results for Δθ = -10.4° to 10.4° are shown. The reflectivity is calculated from the formula (3) with the deviation Δθ from the optical axis. - Here, in a case where the rotation angle θ2 about the
straight line 9 that is perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam is 45°, and the rotation angle θ1 of theoptical separator 3 about theoptical axis 6 is 0°, the reflectivity depending on the incident position ranges from 0% to 4.5%, which varies greatly. - When the rotation angle θ1 of the
optical separator 3 about theoptical axis 6 is adjusted to 20° by the angle adjusting mechanism 7, the reflectivity depending on the incident position ranges from 2.4% to 5.9%. - Further, when the rotation angle θ2 about the
straight line 9 that is perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam is adjusted to 53° by theangle adjusting mechanism 8, the reflectivity depending on the incident position ranges from 3.1% to 4.7%. - As described above, when the angle θ1 of the
optical separator 3 about theoptical axis 6, and the angle θ2 thereof about thestraight line 9 perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam are adjusted, it is possible to average the reflectivity of theoptical separator 3 with respect to the deviation Δθ of the laser beam from theoptical axis 6. - As mentioned above, the
diffuser plate 4 is disposed on the path of the laser beam reflected by theoptical separator 3 in which the angles θ1, θ2 are adjusted (the optical separator in which the reflectivity is averaged with respect to the deviation Δθ of the laser beam from the optical axis 6) ; thus, the laser beam reflected by theoptical separator 3 is uniformly diffused, and such diffused beam of the laser beam is made incident on thephotodetector 5. - The
photodetector 5 is disposed in the post stage of thediffuser plate 4, and measures an intensity of the laser beam diffused by thediffuser plate 4. - According to Embodiment 1, since the
photodetector 5 is disposed in the post stage of thediffuser plate 4, it is possible to accurately make a constant fraction of the beam incident on thephotodetector 5 without changing the position of thephotodetector 5, even when the optical path of the reflected beam is changed at the time of adjusting the angle of theoptical separator 3, or the spatial energy distribution of the laser beam is non-uniform. Thus, it becomes possible to accurately measure the intensity of the laser beam. - Here, since the laser beam is diffused by the
diffuser plate 4, there is no limit for the aperture area of thephotodetector 5; however, in order to measure the power accurately, it is desirable that the aperture area of thephotodetector 5 be smaller than the diffused area of the laser beam. - In this manner, even if a slight variation occurs in the optical path of the laser beam, it becomes possible to measure accurately the intensity of the laser beam without receiving influence thereof.
- In this Embodiment 1, the
optical separator 3,diffuser plate 4, andphotodetector 5 are configured integrally with each other. This is made to prevent the reflected beam from being not incident on thediffuser plate 4 and thephotodetector 5 when the optical path of the reflected beam is changed with the angle adjustment of theoptical separator 3. - That is, since the
optical separator 3,diffuser plate 4, andphotodetector 5 are moved integrally, it is possible to make the reflected beam incident on thediffuser plate 4 andphotodetector 5, even when a deviation of the optical path occurs with the angle adjustment of theoptical separator 3. - Here, when the
optical separator 3 is rotated by the angle θ1 about theoptical axis 6, the reflected beam is similarly rotated by the angle θ1 about theoptical axis 6, whereas when it is rotated by the angle θ2 about thestraight line 9 perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam, the reflected beam is rotated by theangle 2 * θ2 about thestraight line 9. - For this reason, with respect to the rotation about the
straight line 9 perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam, it is required to adjust the angle θ2 within a range such that no reflected beam is leaked from thediffuser plate 4. - However, practically, when the angle θ2 is adjusted, it is not conceivable that the angle is changed beyond the range leaked from the
diffuser plate 4; thus, the above never becomes a major problem. - Furthermore, when the intensity of the laser beam is measured by separating a part of the laser beam, the
optical separator 3 having a smaller reflectivity is desirable in order not to reduce as much as possible the output of the laser beam to be originally output. - On the other hand, if the reflectivity is too small, a sufficient amount of laser beam is not made incident on the
photodetector 5 to thereby cause a measurement error thereof due to noise such as stray light. - Therefore, a rate of the laser beam to be separated by the
optical separator 3 is a degree such that no measurement error in thephotodetector 5 occurs. - Moreover, although it is desirable that the reflectivity of the
optical separator 3 be as small as possible and adjustable for every apparatus, it becomes possible to adjust the rate of the laser beam to be separated by theoptical separator 3 for every apparatus by changing the rotation angle of theoptical separator 3 using theangle adjusting mechanisms 7, 8. - As is clear from the above, according to Embodiment 1, since it is configured such that the
optical separator 3 is disposed in the position that is rotated by the predetermined angle about theoptical axis 6 of the laser beam converged by thelens 2, and further rotated by the predetermined angle about thestraight line 9 perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam, there is rendered an advantageous effect that can measure accurately an intensity of the laser beam without using an expensive optical separator. - That is, when the angle θ1 of the
optical separator 3 about theoptical axis 6 and the angle θ2 about thestraight line 9 perpendicular to theoptical axis 6 of the laser beam and the incident surface of the laser beam are adjusted by theangle adjusting mechanisms 7, 8, it becomes possible to adjust the polarization direction (ratio of the P-wave and S-wave) of the laser beam incident on the reflection surface of theoptical separator 3 and the reflectivities themselves of the P-wave and S-wave. In such a way, even in the converged laser beam having incident angles that differ depending on the incident positions, it becomes possible to average the differences in reflectivity according to the incident positions by the rotation mechanisms. Further, it is possible to avoid a problem of instability in laser output measurement with a partially reflective coating as in the prior art, and thus an accurate laser output measurement can be achieved at low cost. - Note that in this Embodiment 1, there is shown the case where the
angle adjusting mechanisms 7, 8 adjust the angles θ1, θ2 of theoptical separator 3; however, if the position in which the reflectivities of theoptical separator 3 are averaged with respect to the deviations Δθ of the laser beam from theoptical axis 6 is found in advance, theoptical separator 3 may be fixed at that position; thus, in this case, theangle adjusting mechanisms 7, 8 for adjusting the angles θ1, θ2 of theoptical separator 3 become unnecessary. - If it is unnecessary to equip the adjusting
mechanisms 7, 8, the number of components can be reduced to thereby achieve cost reduction. Further, since the movable parts can be reduced, it is possible to enhance reliability of the laser output measuring apparatus. - In the above Embodiment 1, there is shown the case where the laser beam oscillated from the single laser oscillator 1 is made incident on the
lens 2; however, it may be contemplated that laser beams oscillated from a plurality of laser oscillators are made incident on thelens 2. -
Fig. 10 is a side view showing a laser output measuring apparatus according toEmbodiment 2 of the present invention. In the figure, the same reference numerals as those inFig. 1 represent the same or equivalent parts, so that descriptions therefor will be omitted. - In the laser output measuring apparatus of
Fig. 10 , N (N is an integer of 2 or more)laser oscillators -
Fig. 11 is a side view showing a state in which a beam vector VN of the laser beam oscillated from thelaser oscillator 10N is made incident at a deviated angle Δθ with respect to theoptical axis 6. - In
Embodiment 2, the laser beam oscillated from theN laser oscillators 101 to 10N is made incident on thelens 2. - At this time, for example, the beam vector VN of the laser beam oscillated from the
laser oscillator 10N is made incident at the deviated angle Δθ relative to theoptical axis 6, as shown inFig. 11 . - The reflectivity of the
optical separator 3 is calculated as described in the above Embodiment 1 from the above formulae (1) to (3) on the basis of the angle Δθ from theoptical axis 6. - Also in this
Embodiment 2, similarly to the above Embodiment 1, it is possible to average reflectivities on theoptical separator 3 of the laser beams oscillated from theN laser oscillators 101 to 10N, in such a manner thatangle adjusting mechanisms 7, 8 adjust the angles θ1, θ2 of theoptical separator 3 on the basis ofFig. 9 in which calculation results by the formula (3) are shown. Thus, even when theN laser oscillators 101 to 10N are mounted thereon, there is rendered an advantageous effect that an intensity of the laser beam can be measured accurately without using an expensive optical separator. - The laser output measuring apparatus according to the present invention is suited to a case where in adjusting an output of the laser beam oscillated from the laser oscillator, the intensity of the laser beam needs to be measured.
- 1: laser oscillator, 2: lens, 3: optical separator, 4: diffuser plate, 5: photodetector, 6: optical axis of laser beam, 7: angle adjusting mechanism (first angle adjusting mechanism), 8: angle adjusting mechanism (second angle adjusting mechanism), 9: straight line, 101 to 10N: laser oscillators, 101: laser oscillator, 102: optical separator, 103: photodetector, 104: optical axis of laser beam.
Claims (5)
- A laser output measuring apparatus comprising:a lens (2) that converges a laser beam incident thereon;an optical separator (3) that reflects a part of the laser beam converged by the lens (2) according to a Fresnel reflectivity that depends on a polarization direction and an incident angle thereon of the laser beam;a photodetector (5) that measures an intensity of the laser beam reflected by the optical separator, a first angle adjusting mechanism (7) that rotates the optical separator by a predetermined angle about an optical axis of the laser beam converged by the lens, anda second angle adjusting mechanism (8) that rotates the optical separator by a predetermined angle about the straight line perpendicular to the optical axis of the laser beam and the incident surface of the laser beam.
- The laser output measuring apparatus according to Claim 1, wherein the laser beams oscillated by a plurality of laser oscillators are made incident on the lens.
- The laser output measuring apparatus according to Claim 1, wherein the optical separator and the photodetector are configured integrally, and the photodetector is rotated integrally with the optical separator when the optical separator is rotated by the first and second angle adjusting mechanism.
- The laser output measuring apparatus according to Claim 1, wherein the laser beam made incident on the lens is a substantially linearly polarized beam.
- The laser output measuring apparatus according to Claim 1, further comprising a diffuser plate that is disposed between the optical separator and the photodetector, and that diffuses the laser beam reflected by the optical separator, and makes the diffused light from the laser beam incident on the photodetector.
Applications Claiming Priority (1)
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PCT/JP2011/007314 WO2013098887A1 (en) | 2011-12-27 | 2011-12-27 | Laser output measuring apparatus |
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EP2799823A4 EP2799823A4 (en) | 2015-09-23 |
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US (1) | US9534953B2 (en) |
EP (1) | EP2799823B1 (en) |
JP (1) | JP6025749B2 (en) |
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CN103649696B (en) * | 2011-10-11 | 2016-05-18 | 三菱电机株式会社 | Laser output measuring mechanism |
EP3168290B1 (en) | 2014-07-07 | 2021-12-08 | Logos Biosystems, Inc. | Apparatus for clearing tissue using electrophoresis |
DE102016009475B4 (en) * | 2016-08-05 | 2019-06-19 | Primes GmbH Meßtechnik für die Produktion mit Laserstrahlung | Beam power measurement with expansion |
CN107234345B (en) * | 2017-07-14 | 2019-06-14 | 大族激光科技产业集团股份有限公司 | A kind of laser cutting system and its cutting method |
JP7270169B2 (en) * | 2018-05-15 | 2023-05-10 | パナソニックIpマネジメント株式会社 | LASER DEVICE AND LASER PROCESSING DEVICE USING THE SAME |
CN110346782A (en) * | 2019-05-31 | 2019-10-18 | 华东师范大学 | A kind of correcting method of long range ground three-dimensional laser radar echo strength data |
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- 2011-12-27 JP JP2013551033A patent/JP6025749B2/en not_active Expired - Fee Related
- 2011-12-27 WO PCT/JP2011/007314 patent/WO2013098887A1/en active Application Filing
- 2011-12-27 EP EP11878355.4A patent/EP2799823B1/en not_active Not-in-force
- 2011-12-27 CN CN201180075886.0A patent/CN104011516B/en not_active Expired - Fee Related
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US9534953B2 (en) | 2017-01-03 |
CN104011516B (en) | 2016-08-24 |
WO2013098887A1 (en) | 2013-07-04 |
JPWO2013098887A1 (en) | 2015-04-30 |
EP2799823A1 (en) | 2014-11-05 |
JP6025749B2 (en) | 2016-11-16 |
US20140285804A1 (en) | 2014-09-25 |
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